This principle of the Constitution is closely connected with Separation of Powers. The Founding Fathers wanted to make sure that the three different branches of government, the legislative, executive and judicial, would be able to limit each other’s powers. For example, the President can appoint ambassadors or federal judges, but only with the approval of the Senate, the upper house of Congress. This is a very important way to protect the citizens’ liberties and ensure that no one group of people becomes too powerful. Each branch always has the other two branches looking over their shoulder.